1. Field of the Invention
The present invention relates to a riding type vehicle. More particularly, the present invention relates to a riding type vehicle that includes an automatic transmission that executes a shift change through a clutch actuator and a shift actuator.
2. Description of the Related Art
When a gear speed change is carried out in a motorcycle, generally, the gear speed change is carried out by disengaging a clutch through a clutch lever operated the hand and switching gears by a foot operation to execute the shift change. During such operation, the clutch is successively engaged by operating the clutch lever by the hand. In recent years, there has been proposed a technology for executing an automatic gear speed change operation that does not use a servo motor. However, in comparison with the manual operation, a number of problems are posed by such automatic systems.
For example, when the gear speed change is carried out, a state of the motorcycle (particularly, a state of the clutch) and a timing of the shift change are closely related to each other. As such, the automatic speed change operation is extremely difficult to control. Specifically, when the clutch is expanded by temperature changes (for example, thermal expansion of about 100 μm) or the clutch is worn (for example, wear of about 100 μm), the timing of the clutch can be shifted. This can result in unsmooth shift change operation.
In a manual system, when a person (rider) carries out the gear speed change operation, even when the clutch is exposed to different temperature states (e.g., summer or winter, day or night), or when the clutch is in a new product state or a worn state, the rider instantly determines the states by experience or knowledge and the shift change can be executed smoothly by a flexible and precise operation of the hand and the foot. On the other hand, when the gear speed change operation is executed by a motor or the like, all of the timings of the shift change need to be controlled by an operating apparatus in accordance with the state of the motorcycle, and it can be difficult to firmly and smoothly execute the clutch operation and the shift operation.
Further, in order to simplify the shift operation of the motorcycle, there is disclosed in Japanese patent references JP-A-68-152938 and JP-A-4-266619 a transmission that uses a servo motor that driven based on an output signal of a switch cooperatively moved with ON/OFF operation of a clutch such that a shift change operation is automatically carried out by the servo motor.
However, there remains many challenges associated with a reduction to practice of a motorcycle capable of automatically executing a shift change by using a clutch actuator and a shift actuator.